Where it came from and what we know now

Similar documents
Dalton Thompson Rutherford Bohr Modern Model ("Wave. Models of the Atom

What is a theory? An organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena

Development of Atomic Theory Elements of chemistry- Atoms, the building blocks of matter Video

Atoms and their structure

General Chemistry Standard : Identify the significance of the various outcomes of Thomson s and Rutherford s experiments

What is matter? Matter is anything that has mass and takes up space. Matter is made up of atoms.

SNC1D1 History of the Atom

CHAPTER 4: Matter is Made up of Atoms

DEMOCRITUS - A philosopher in the year 400 B.C. - He didn t do experiments and he wondered if atoms kept on being divided, that there would only be

Atomic Structure. History of Atomic Theory

Passing an electric current makes a beam appear to move from the negative to the positive end.

Chapter 11 Study Questions Name: Class:

Name Date Class DEFINING THE ATOM

atomos is a Greek word which means indivisible

Chapter 4. Atomic Structure

Democritus 460 BC 370 BC. First scholar to suggest that atoms existed. Believed that atoms were indivisible and indestructible.

8.5 Atomic Structure

CHAPTER 4: THE ATOM PHYSICAL SCIENCE

Atomic Structure Early Theories Democritus: 4 B.C.: atom Dalton: atoms cannot Thomson: Cathode Ray Tubes Rutherford:

Atomic Structure. A model uses familiar ideas to explain unfamiliar facts observed in nature.

History of Atomic Theory

Atomic Structure. Defining the Atom. Defining the Atom. Sizing up the Atom. Structure of the Atom 9/18/2012

Atomic Structure. ppst.com

CHAPTER 3 THE ATOM. 1. Matter is composed extremely small particles called atoms

Vocabulary Review. Atom Cathode Ray Electrons Protons Neutrons Nucleus

Atomic Structure. For thousands of years, people had many ideas about matter Ancient Greeks believed that everything was made up of the four elements

Early Models of the Atom

Teacher: Mr. gerraputa. Name: Base your answer to the question on the information below. Given the electron dot diagram:

Fill in the Following Table in your notes (assume an atom unless otherwise stated: Symbol Protons Electrons Neutrons Atomic # Mass # 24 Na

Chapter 4: Atomic Structure Section 4.1 Defining the Atom

The History of the Atom. How did we learn about the atom?

EARLY VIEWS: The Ancient Greeks

Early Atomic Models. Atoms: the smallest particle of an element that retains the properties of that element.

Atomic Theories Chapter 4.1. How do we know about atoms when no one has ever seen inside an atom?

Atomic Theory. Democritus to the Planetary Model

Chap 4 Bell -Ringers

CHAPTER -4 STRUCTURE OF ATOM CONCEPT DETAILS

Atomic Structure. How do you discover and study something you can t see?

Chapter 4 Atomic Structure. Chemistry- Lookabaugh Moore High School

An Introduction to Atomic Theory. VCE Chemistry Unit 1: The Big Ideas of Chemistry Area of Study 1 The Periodic Table

Chapter 3: Atomic Theory

H CHEM - WED, 9/7/16. Do Now Be ready for notes. Sigfig review problem. Agenda Atomic Theory. Homework. Error Analysis

CHEMISTRY 11 UNIT REVIEW: ATOMIC THEORY & PERIODIC TRENDS

Democritus & Leucippus (~400 BC) Greek philosophers: first to propose that matter is made up of particles called atomos, the Greek word for atoms

CH4 HOMEWORK : ATOMIC STRUCTURE

ATOMIC STRUCTURE. Name: Period: Date: 1) = a generalization of scientific observations that what happens (does explain)

Unit Two Test Review. Click to get a new slide. Choose your answer, then click to see if you were correct.

The idea of an atom began about 400 B.C. with many Greek philosophers, like Democritus, working to figure out what everything was made of.

Atomic Theory. Developing the Nuclear Model of the Atom. Saturday, January 20, 18

7.1 Development of a Modern Atomic Theory

Notes:&&Unit&4:&Atomics& & & & & & & & & & & & & & & & &

Chapter 4. History of the atom. History of Atom Smallest possible piece? Atomos - not to be cut. Atoms and their structure

) The nucleus of an atom, when compared to the entire atom, is (Circle two).

BEGINNING OF ATOMIC THEORY

Atomic Theory. Early models

tomic tructure Chapter 3

Get out your diagram from your research paper. Get out a sheet of paper to take some notes on.

CHAPTER 3. Atoms: The Building Blocks of Matter

The following is a quote by Democritus (c. 460 c. 370 bce). Paraphrase this quote in your own words in your science journal.

Who came up with the first theory of atoms?

1 Development of the Atomic Theory

Structure of matter I

Unit 3. The Atom & Modern Atomic Theory

1. Based on Dalton s evidence, circle the drawing that demonstrates Dalton s model.

Democritus thought atoms were indivisible & indestructible Lacked experimental support 4 th century B.C.

The structure of Atom III

Warm Up 9/17/12. How long have people been interested in understanding matter and its structure? A. Thousands of years. B.

AP Atomic Structure Models

Democritus s ideas don t explain chemical behavior & lacked experimental support.

CHEMISTRY 11 UNIT REVIEW: ATOMIC THEORY & PERIODIC TRENDS

Exam Accelerated Chemistry Study Sheet Chap 04 The Atom/Periodic Table

Section 3.1 Substances Are Made of Atoms

Name Date Class ATOMIC STRUCTURE

UNIT 2 - ATOMIC THEORY

Chemistry. Robert Taggart

Name: Date: Blk: Dalton Thomson Rutherford Bohr THOMSON

Name Class Date. Section: Development of the Atomic Theory THE BEGINNING OF ATOMIC THEORY

Atomic Theory. Why do we believe that all matter is made of atoms?

Atoms, Molecules, Formula, and Subatomic Particles

Unit 2 Atomic Structure and Nuclear Chemistry

Nuclear Chemistry. Atomic Structure Notes Start on Slide 20 from the second class lecture

Chapter 8 Composition of the Atom

What is the current atomic model?

Atomic Structure Discovered. Dalton s Atomic Theory. Discovery of the Electron 10/30/2012

Atomic Theory: Early Models of the Atom:

ATOM. Rich -Paradis. Early Thoughts Aristotle-- Continuous theory. Matter can be divided indefinitely. Greeks

Early Atomic Theory. Alchemy. The atom

Atoms: The Building Blocks of Matter CHAPTER 3

Memorial to a Scientist

DescribeDemocritus s Democritus s ideas

History of the OBJECTIVES. ESSENTIAL QUESTION What evidence is there for the existence of atoms and their sub-atomic particles?

Atomic Theory Development

Early Atomic Theories and the Origins of Quantum Theory. Chapter 3.1

1 The Development of Atomic Theory

Atomic Theory. The History of Atomic Theory

Ancient Atomic Theories

Atomic Models. A model uses familiar ideas to explain unfamiliar facts observed in nature. A model can be changed as new information is collected.

HISTORY OF THE ATOM ATOMA

Section Review. Development of the Atomic Theory USING VOCABULARY UNDERSTANDING CONCEPTS. Skills Worksheet

Regents Chemistry Unit 1 Atomic Concepts. Textbook Chapters 3 & 4

Transcription:

Where it came from and what we know now

History of the Atom The first mention of the atom came from Democritus in ancient Greece He suggested that the universe was made up of small, indivisible units called atoms He believed that the differences in the atoms had to do with their shape, and that these differing shapes gave them their properties 460-370 (BC) Unfortunately, he had no evidence for his theory. He was a philosopher all they do is think

History of the Atom The next big step in atomic theory came from John Dalton 1766-1844 He noticed that all atoms of a certain element were exactly the same and that when different atoms combined, they formed new compounds. He observed the reactions of chemicals with each other and saw that they consistently combined the same way.

1 = Hydrogen 2= Nitrogen 3= Carbon 4= Oxygen Etc.

History of the Atom J. J. Thomson discovered the presence of negatively charged particles of an atom His Cathode Ray Tube experiment allowed him to discover that, when the cathode ray was introduced to a magnetic field, the ray would deflect towards the positive terminal 1856-1940 He created the plum pudding theory of the atom, where the raisins in the pudding represented the electrons

History of the Atom 1856-1940 Cathode Ray Tube Experiment

History of the Atom Earnest Rutherford, using alpha particles and gold foil, discovered that most of the mass of an atom was centrally located 1871-1937

History of the Atom

What the atom now looks like! 1. The universe is made up of tiny indivisible units, we now call atoms 2. All atoms of the same element are exactly alike, and can combine with other elements to create compounds 3. Atoms have negatively charged particles 4. Most of the mass of an atom is concentrated at the center

What is the atom composed of? Protons Positively charged, located in the nucleus Neutrons No charge, located in the nucleus Electrons Negative Charge, Located in the electron cloud

What is the atom made up of? Protons Positively charged, located in the nucleus Neutrons No charge, located in the nucleus Electrons Negative Charge, Located in the electron cloud Particle Charge Mass (Kg) Location in the atom Proton +1 1.67 x 10-27 Nucleus Neutron 0 1.67 x 10-27 Nucleus Electron -1 9.11 x 10-31 Electron cloud

What do the protons tell us about the element? Protons tell us what element it is. It is the atomic number. Oxygen has 8 The atomic mass of oxygen is 16. It has 8 neutrons, on average protons Neutrons add mass to the atom. To get the atomic mass, you add the number of protons to the number of neutrons. The number of neutrons in an atom is not constant.

What they tell us about the atom If an atom has a different number of neutrons than the stable element, it is said to be an isotope. The atomic mass is a ratio of all of the isotopes that naturally exist in the world

Why are electrons so important? Electrons are found in what is known as the electron cloud. The cloud consists of different energy orbitals. The specific location of each electron is unknowable since they are constantly transitioning from one orbital to the next.

Valence electrons The valence electrons are located on the outer most orbital of the electron, and can be determined by which group of the periodic table they reside in. How many valence electrons an element has determines its reactivity

Valence electrons As we move from left to right across the groups, we increase our valence electrons

What does this tell us? Atoms want to be stable, and an atom is most stable when its outer shell is full. A full shell has 8 electrons.

Valence Electrons Lets look at the first period. 1 Valence electron 6 Valence electrons Ions will be +1 Ions will be -2

A new way to look at mass Moles: The S.I. base unit we use to measure the amount of a substance. 1 mole is defined as the number of atoms in 12 grams of carbon-12 There are 6.022 x 10 23 atoms in 12 grams of carbon-12. this is known as Avogadro s number

Converting between mass and moles Ex 1. Convert 2 moles of lead to mass:type equation here. 2 Moles Pb 207.19 g 1 Mole Pb = 414.38 g Pb Ex 2. How many moles are there in 54.5 grams of carbon? 54.5 g C 1 Mole C 12.011 g = 4.54 moles C

Modern Atomic Theory The atom is made up of a nucleus with protons and neutrons, and the electrons are in the electron cloud. We now know that electrons exist is very specific energy levels; never in between. e - e - e - e - e - GROUND STATE

Modern atomic Theory The electrons jump from level to level when they are bombarded by photons and other energy sources e - e -

Modern Atomic Theory The number of energy levels filled depends on the number of electrons present. Energy level Number of orbitals by type s p d f Total number of orbitals Number of electrons 1 1 1=1 2 2 1 3 1+3=4 8 3 1 3 5 1+3+5=9 18 4 1 3 5 7 1+3+5+7=16 32

Modern Atomic Theory Element Number of electrons Orbital Hydrogen (H) 1 1s 1 Carbon (C) 6 1s 2 2s 2 2p 2 Oxygen (O) 8 1s 2 2s 2 2p 4 Neon (Ne) 10 1s 2 2s 2 2p 6 Sulfur (S) 16 1s 2 2s 2 2p 6 3s 2 3p 4 Potassium (K) 19 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1

Modern Atomic Theory Oxygen (O): 1s 2 2s 2 2p 4 8 P 8N

2024 © sciencedocbox.com Privacy Policy | Terms of Service | Feedback